The present invention relates to phosphated derivatives of castor oil and hydrogenated castor oil as well as phosphated esters of ricinoleic acid. The inclusion of the phosphate group results in improved water solubility and a series of dispersants and emulsifiers that provide excellent pigment dispersing properties.
Castor oil is a unique triglyceride. It is derived from Ricinus communis L. The castor plant grows wild in many subtropical and tropical areas. Today Brazil, China and India provide over 90% of the oil. Castor oil contains a large content of hydroxy containing compounds that are unsaturated.
Castor Oil is a clear, viscous, light colored fluid that is nondrying and quite stable. The Purity of Castor Oil occurs with remarkable uniformity. Regardless of country of origin, or season it is grown, the composition and chemical properties remain within a very narrow range. Castor Oil has broad compatibility with oils, waxes, natural resins, and gums.
Another unique aspect of castor oil is the high level of ricinoleic acid in the molecule. Castor oil contains 89% of the acid, which conforms to the following structure; 
When hydrogenated the double bond is lost giving hydrogenated ricinoleic, or 12-hydroxy stearic acid. 
When the acids derived from castor (ricinoleic acid) are reacted with alcohols having 6 to 22 carbon atoms the resulting esters are also suitable candidates for phosphation. 
wherein R is CH3xe2x80x94(CH2)nxe2x80x94 and n is an integer ranging from 5 to 21.
When the acids derived from hydrogenated castor (12-hydroxy-stearic acid) are reacted with alcohols having 6 to 22 carbon atoms the resulting esters are also suitable candidates for phosphation. 
wherein R is CH3xe2x80x94(CH2)nxe2x80x94 and n is an integer ranging from 5 to 21.
The present invention relates to a series of compounds in which the hydroxyl group in alkyl group of castor is phosphated, resulting in a surface-active agent that has outstanding pigment dispersing properties. Included within this definition of castor compounds are castor oil (a triglyceride), hydrogenated castor oil, ricinoleic acid and 12-hydroxystearic acid compounds.
The invention also relates to the utilization of these phosphated materials as surface-active agents in personal care and industrial applications. These materials function as pigment wetters, and emulsifiers. As pigment wetters the compounds of the present invention coat the hydrophobic pigment making is disperse in aqueous dispersions, for formulation in products in which the color is desired. The compounds of the present invention have the proper balance of water loving and oil loving portions to allow for the formation of very stable pigment dispersions.
It is the objective of the present invention to provide surface active agents derived from the phosphation of castor oil, hydrogenated castor oils or esters derived there from. The surface-active agents are outstanding pigment dispersants. Additionally, the objective of the present invention is the utilization of the compounds of the present invention with pigments to make dispersions of outstanding stability.
In one particular aspect of the present invention, castor oil is phosphated using poly phosphoric acid (PPA). The resulting product ranges from water dispersible, when only one of the three hydroxyl groups is phosphated, to water soluble when all three are phosphated.
In one aspect the compounds of the present invention are phosphated trglycerides conforming to the following structure 
wherein;
R is selected from the group consisting of xe2x80x94(CH2)2xe2x80x94 and xe2x80x94CHxe2x80x94CHxe2x80x94;
R1 is xe2x80x94P(O)xe2x80x94(OH)2 
R2 and R3 are independently selected from the group consisting of H and xe2x80x94P(O)xe2x80x94(OH)2.
One subset set of this generic set compounds of the present invention conforms to the following structure based upon hydrogenated castor oil; 
wherein;
R1 is xe2x80x94P(O)xe2x80x94(OH)2 
R2 and R3 are independently selected from the group consisting of H and xe2x80x94P(O)xe2x80x94(OH)2.
Another subset of compounds of the present invention is based upon castor oil and conforms to the following structure; 
wherein;
R1 is xe2x80x94P(O)xe2x80x94(OH)2 
R2 and R3 are independently selected from the group consisting of H and xe2x80x94P(O)xe2x80x94(OH)2.
Another set of compounds conforms to the following structure; 
Finally, another set of compounds of the present invention conforms to the following structure; 
wherein R is CH3xe2x80x94(CH2)nxe2x80x94 and n is an integer ranging from 5 to 21.
The reaction with castor oil is as follows; 
The reaction for the hydrogenated castor is identical to that of the castor, except the double bond is not present. This results in a phosphated castor wax. The reaction proceeds as follows: 
The changing of the amount of PPA will allow for phosphating the remaining hydroxyl groups resulting in a di-phosphate (if 2 equivalents of PPA are used), or a tri-fosfate (if 3 equivalents of PPA are used)
Phosphated ricinoleic acid ester conform to the following structure 
wherein;
R is xe2x80x94(CH2)nxe2x80x94CH3 
R1 is xe2x80x94P(O)xe2x80x94(OH)2 
n is an integer ranging from 5 to 21.
Phosphated 12-hydroxy stearic acid esters conform to the following structure 
wherein;
R is xe2x80x94(CH2)nxe2x80x94CH3 
R1 is xe2x80x94P(O)xe2x80x94(OH)2 
n is an integer ranging from 5 to 21
In a preferred embodiment the phosphated compounds belong to class 1 and conforming to the following structure; 
wherein;
R1 is xe2x80x94P(O)xe2x80x94(OH)2 
R2 and R3 are independently selected from the group consisting of H and xe2x80x94P(O)xe2x80x94(OH)2.
In a preferred embodiment of class 1 R2 and R3 are H.
In a preferred embodiment of class 1 R2 is xe2x80x94P(O)xe2x80x94(OH)2 and R3 is H.
In a preferred embodiment of class 1 R2 and R3 are both xe2x80x94P(O)xe2x80x94(OH)2 
In a preferred embodiment of class 2 the phosphated compound conforming to the following structure 
wherein;
R1 is xe2x80x94P(O)xe2x80x94(OH)2 
R2 and R3 are independently selected from the group consisting of H and xe2x80x94P(O)xe2x80x94(OH)2.
In a preferred embodiment of class 2 R2 and R3 are H.
In a preferred embodiment of class 2 R2 is xe2x80x94P(O)xe2x80x94(OH)2 and R3 is H.
In a preferred embodiment of class 2 R2 and R3 are both xe2x80x94P(O)xe2x80x94(OH)2 
In a preferred embodiment of class 3 the phosphated compound conforming to the following structure 
wherin;
R is xe2x80x94(CH2)nxe2x80x94CH3 
R1 is xe2x80x94P(O)xe2x80x94(OH)2 
n is an integer ranging from 5 to 21.
In a preferred embodiment of class 3 n is 5.
In a preferred embodiment of class 3 n is 11.
In a preferred embodiment of class 3 n is 17.
In a preferred embodiment of class 3 n is 21.
In a preferred embodiment of class 4 the phosphated compound conforming to the following structure 
wherein;
R is xe2x80x94(CH2)nxe2x80x94CH3;
R1 xe2x80x94P(O)xe2x80x94(OH)2;
n is an integer ranging from 5 to 21.
In a preferred embodiment of class 3 n is 5.
In a preferred embodiment of class 3 n is 11.
In a preferred embodiment of class 3 n is 17.
In a preferred embodiment of class 3 n is 21.